Free radicals have been implicated in the pathogenesis of diverse metabolic disorders including cancer. Therefore, fighting against free radicals has become an important strategy in the prevention or treatment of such diseases, in addition to direct or indirect anticancer chemotherapy. Sarcocephalus pobeguinii has been used traditionally to treat various diseases in which excess production of free radicals is implicated, warranting investigation of its free radical scavenging, anticancer and anti-inflammatory activity. In the present study, extracts from leaves, fruits, roots and bark of Sarcocephalus pobeguinii were evaluated on four human cancer cell lines (MCF-7, HeLa, Caco-2 and A549 cells) and a non-cancerous cell line for their antiproliferative potential. The cells were incubated with the plant extracts for 48 h at 37 °C in a 5% CO2 humidified environment and their cytotoxic effect was determined using the tetrazolium-based colorimetric (MTT) assay. The radical inhibition was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging techniques. The nitric oxide inhibitory activity was determined using LPS-activated RAW 264.7 macrophages. The correlation between radical scavenging capacity and antiproliferative activity was also analysed. The extract from leaves of Sarcocephalus pobeguinii (LSP) exhibited the highest cytotoxic effect on all four of the human cancer cell lines but with some cytotoxicity to the normal Vero cells. However, the LSP extract had the best selectivity index, ranging from 3.15 to 18.28. Also, antioxidant and anti-inflammatory assays indicated that the LSP extract had the highest radical scavenging capacity of all the extracts. A positive linear correlation was found between free radical scavenging ability and antiproliferative activity against the four cancer cell lines, with the highest correlation factor (R2 = 0.9914) obtained between DPPH inhibition and antiproliferative activity against A549 cells. The high selectivity index of the Sarcocephalus pobeguinii leaf extract indicates the potential of using this extract in cancer therapy. Furthermore, the positive correlation between free radical scavenging and antiproliferative activity suggests that the radical scavenging capacity of extracts may contribute to a prediction of their anticancer property.

Background:Sarcocephalus pobeguinii (Hua ex Pobég) is used in folk medicine to treat oxidative-stress related diseases, thereby warranting the investigation of its anticancer and anti-inflammatory properties. In our previous study, the leaf extract of S. pobeguinii induced significant cytotoxic effect against several cancerous cells with high selectivity indexes towards non-cancerous cells.Aim: The current study aims to isolate natural compounds from S. pobeguinii, and to evaluate their cytotoxicity, selectivity and anti-inflammatory effects as well as searching for potential target proteins of bioactive compounds.Methods: Natural compounds were isolated from leaf, fruit and bark extracts of S. pobeguinii and their chemical structures were elucidated using appropriate spectroscopic methods. The antiproliferative effect of isolated compounds was determined on four human cancerous cells (MCF-7, HepG2, Caco-2 and A549 cells) and non-cancerous Vero cells. Additionally, the anti-inflammatory activity of these compounds was determined by evaluating the nitric oxide (NO) production inhibitory potential and the 15-lipoxygenase (15-LOX) inhibitory activity. Furthermore, molecular docking studies were carried out on six putative target proteins found in common signaling pathways of inflammation and cancer.Results: Hederagenin (2), quinovic acid 3-O-[α-D-quinovopyranoside] (6) and quinovic acid 3-O-[β-D-quinovopyranoside] (9) exhibited significant cytotoxic effect against all cancerous cells, and they induced apoptosis in MCF-7 cells by increasing caspase-3/-7 activity. (6) showed the highest efficacy against all cancerous cells with poor selectivity (except for A549 cells) towards non-cancerous Vero cells; while (2) showed the highest selectivity warranting its potential safety as a chemotherapeutic agent. Moreover, (6) and (9) significantly inhibited NO production in LPS-stimulated RAW 264.7 cells which could mainly be attributed to their high cytotoxic effect. Besides, the mixture nauclealatifoline G and naucleofficine D (1), hederagenin (2) and chletric acid (3) were active against 15-LOX as compared to quercetin. Docking results showed that JAK2 and COX-2, with the highest binding scores, are the potential molecular targets involved in the antiproliferative and anti-inflammatory effects of bioactive compounds.Conclusion: Overall, hederagenin (2), which selectively killed cancer cells with additional anti-inflammatory effect, is the most prominent lead compound which may be further investigated as a drug candidate to tackle cancer progression.

Background: Eating Cola acuminata and Garcinia cola nuts in African societies symbolizes in socio-cultural hospitality. They stimulate the nervous system, reduce fatigue and sleep. Objectives: To determine the phenolic composition and bioactivities of G. kola and C. acuminata. Materials and Methods: Hydro-ethanol extracts of the nuts were prepared and their phenolic profiles determined using HPLC-DAD. Antioxidant, anticholinesterase, antidiabetic, antimicrobial, antibiofilm and anti-quorum sensing properties were determined. Results: The most abundant phenolic compound was caffeic acid (105.4±0.75 mg/g) in C. acuminata and myricetin (277.2±0.90 mg/g) in G. kola. The extracts showed good antioxidant activity in five complementary assays and G. kola was more active than both α-tocopherol and BHA standards in the DPPH • , CUPRAC and ABTS •+ assays while C. acuminata was more active than only the α-tocopherol standard in the same assays. Activities were close to those of standards in the β-Carotene-linoleic acid and metal chelation assays. Both extracts had good inhibition of Butyrylcholinesterase (BChE) and Acetylcholinesterase (AChE) with IC 50 values 63.27±0.98 µg/mL and 94.15±1.05 µg/mL for C. acuminata and G. kola respectively compared to 5.50±0.25 µg/mL for galantamine in the AChE assay. In the BChE assay, the inhibitory activity was higher for G. kola (IC 50 = 38.66±0.80 µg/ mL) that the standard galantamine (IC 50 = 42.20±0.48 µg/mL) while that for C. acuminata (IC 50 = 87.31±0.77 µg/mL) was moderate. The extracts inhibited α-amylase and α-glucosidase with G. kola (IC 50 =18.43±0.74 µg/mL) being more active than standard acarbose (IC 50 =20.52±0.84 µg/mL in the α-glucosidase assay. The nuts could inhibit expression of virulence factors in Chomobacterium violaceum CV12472 by disrupting violacein production and flagellated Pseudomonas aeruginosa PA01 by disrupting swarming motility. Conclusion: The results indicate good nutraceutical potential of both nuts.

From Rinorea oblongifolia fruits, 3-Nor-4β-friedelan-24-ol (1) and 3-decyl-6,7,8-trimethoxy-2H,5H-furo[4,3,2-de]isochromene-2,5-dione (4), new derivatives alongside, 28-hydroxyfriedelan-3-one (2), friedelin (3), 3,3’,4,4’,5’-pentamethylcoruleoellagic acid (5), hexamethylcoruleoellagic acid (6), 3’,4,4’,5,5’-pentamethylcoruleoellagic acid (7), and fatty compounds 8-11 were isolated and characterized using HRESIMS, EIMS, 1D and 2D NMR. In vitro enzyme inhibition of compounds 1, 2, 4, 5, 6 and 7 were evaluated on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase, urease and tyrosinase. Against AChE and BChE, the phenolic compounds 4, 5, 6, and 7 had good activity probably due to the phenolic nature and methoxy substituents. Compounds 4, 5, 6 and 7 exhibited good α-glucosidase inhibition especially compound 4 whose IC₅₀ = 42.45 ± 0.46 µg/mL was close that of acarbose (IC₅₀ = 20.52 ± 0.84 µg/mL) standard drug. Urease and tyrosinase were appreciably inhibited by the compounds. Overall results of enzyme inhibitory assays indicate Rinorea oblongifolia, fruits and its constituents as potential remedy for enzymatic disorders. Graphical Abstract